With over 65 million people in the United States who have recovered from COVID-19, the Centers for Disease Control and Prevention (CDC) have released new data shifting the formerly dismissed debate about natural immunity against COVID-19. The new data indicate that prior infections provided greater immunity than vaccines alone, even though the CDC continues to emphasize vaccination as the safest strategy for protecting against SARS-CoV-2.
The CDC report acknowledges what many prior studies have suggested — that surviving COVID-19 provides excellent natural immunity not only to repeat infection but also to hospitalization and death. This was especially the case after the Delta variant, with natural immunity clearly being more protective against infection than vaccination.
This CDC acknowledgement has been slow in coming, despite the fact that multiple, large studies from around the world showed that people who recovered from COVID-19 have low rates of SARS-CoV-2 reinfection. One laboratory study of 9119 recovered people found that only 0.7 percent became re-infected. Another study conducted in Austria found that the frequency of hospitalization due to a repeated infection was five per 14,840 (0.03 percent). A large Israeli study, which was not peer reviewed, showed having Covid once conferred much greater immunity than the vaccine.
These studies show the power of the human immune system providing protection from reinfection with a strong and persistent response for 10 months of follow-up. Yet, it is unknown how long this protective immunity will last. Many systemic viral infections, such as measles, confer long-term, if not lifelong, immunity, whereas others, such as influenza, do not (due to changes in viral genetics). Researchers are limited by the lack of current follow-up data to know the duration of this protection.
It remains unclear how these antibody levels correlate with future protection against emerging variants. Another study highlighted the possibility of extended protection with recovered individuals showing “a robust antigen-specific, long-lived humoral immune memory response.”
Although the CDC finally recognized natural immunity, it continues to promote vaccination as the primary recommendation for COVID prevention for nearly everyone. That may not be necessary or appropriate for many Americans with post-infection immunity. And the disadvantage of COVID-19 vaccines is that they are designed to produce antibodies that attack only one part of the virus, the spike protein. As the spike protein keeps mutating, vaccine efficacy wanes with time. On the other hand, a COVID infection provides a broader, multi-variant immune protection, including a greater ability to defend against any future SARS-CoV-2 virus variants.
Many European countries now recognize that immunity due to prior infection is equal to vaccination. For instance, in Switzerland, residents who can prove recovery from a SARS-CoV-2 infection through a positive PCR or other test in the past 12 months are considered equally protected as those who have been fully vaccinated.
Most corporate media failed to follow the depth and breadth of scientific studies around natural immunity. Fox News is a notable the exception. Its leading medical consultant, Marty Makary, a public health researcher at Johns Hopkins University, has included discussion of natural immunity and downplaying therapeutics as “covid mistakes” by the CDC and other medical experts.
Jeffrey Klausner and Noah Kojima, “The CDC Is Finally Recognizing ‘Natural Immunity’ — Legislators Should Follow Suit,” The Hill, February 2, 2022.
Meredeth Wadman, “Having Sars-Cov-2 Once Confers Much Greater Immunity than a Vaccine—But Vaccination Remains Vital,” Science, August 26, 2021.
Student Researcher: Jayda Flenory (San Francisco State University)
Faculty Evaluator: Kenn Burrows (San Francisco State University)